## Reading layer `US_county_1880' from data source `D:\clio-II\mapping-viz-essay\us_county_2\US_county_1880.shp' using driver `ESRI Shapefile'
## converted into: POLYGON
## Simple feature collection with 2614 features and 20 fields
## geometry type:  MULTIPOLYGON
## dimension:      XY
## bbox:           xmin: -5439121 ymin: -1329871 xmax: 2255854 ymax: 4591568
## epsg (SRID):    NA
## proj4string:    +proj=aea +lat_1=29.5 +lat_2=45.5 +lat_0=37.5 +lon_0=-96 +x_0=0 +y_0=0 +datum=NAD83 +units=m +no_defs
## Reading layer `US_county_1890' from data source `D:\clio-II\mapping-viz-essay\US_county_1\US_county_1890.shp' using driver `ESRI Shapefile'
## converted into: POLYGON
## Simple feature collection with 2799 features and 20 fields
## geometry type:  MULTIPOLYGON
## dimension:      XY
## bbox:           xmin: -5439121 ymin: -1329871 xmax: 2255854 ymax: 4591568
## epsg (SRID):    NA
## proj4string:    +proj=aea +lat_1=29.5 +lat_2=45.5 +lat_0=37.5 +lon_0=-96 +x_0=0 +y_0=0 +datum=NAD83 +units=m +no_defs